content: /*
   * Copyright (c) 2009 Andrejs Jermakovics.
   * 
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *     Andrejs Jermakovics - initial implementation
   */
  package it.unibz.instasearch.indexing.querying;
  
  import it.unibz.instasearch.indexing.Field;
  
  import java.util.HashMap;
  
  import org.apache.lucene.index.Term;
  import org.apache.lucene.search.PrefixQuery;
  import org.apache.lucene.search.Query;
  import org.apache.lucene.search.TermQuery;
  import org.apache.lucene.search.WildcardQuery;
  
  /**
   * Converts field aliases to actual field names
   */
  public class FieldAliasConverter extends QueryVisitor {
  
  	private static HashMap<String, Field> aliases = new HashMap<String, Field>();
  
  	static {
  		aliases.put("project", 		Field.PROJ);
  		aliases.put("filetype",		Field.EXT);
  		aliases.put("type", 		Field.EXT);
  		aliases.put("workingset",	Field.WS);
  		aliases.put("age",			Field.MODIFIED);
  		aliases.put("folder",		Field.DIR);
  	}
  	
  	/**
  	 * 
  	 */
  	public FieldAliasConverter() {
  	}
  	
  	@Override
  	public Query visit(TermQuery termQuery, Field termField) {
  		
  		Term t = termQuery.getTerm();
  		
  		if( termField == null && aliases.containsKey(t.field()) ) {
  			Field field = aliases.get(t.field());
  			Term newTerm = field.createTerm(t.text());
  			TermQuery newTermQuery = new TermQuery(newTerm);
  			return newTermQuery;
  		}
  		
  		return super.visit(termQuery, termField);
  	}
  	
  	@Override
  	public Query visit(PrefixQuery prefixQuery, Field termField) {
  		
  		Term t = prefixQuery.getPrefix();
  		
  		if( termField == null && aliases.containsKey(t.field()) ) {
  			Field field = aliases.get(t.field());
  			Term newTerm = field.createTerm(t.text());
  			PrefixQuery newTermQuery = new PrefixQuery(newTerm);
  			return newTermQuery;
  		}
  		
  		return super.visit(prefixQuery, termField);
  	}
  	
  	@Override
  	public Query visit(WildcardQuery wildcardQuery, Field termField) {
  		
  		Term t = wildcardQuery.getTerm();
  		
  		if( termField == null && aliases.containsKey(t.field()) ) {
  			Field field = aliases.get(t.field());
  			Term newTerm = field.createTerm(t.text());
  			WildcardQuery newTermQuery = new WildcardQuery(newTerm);
  			return newTermQuery;
  		}
  		
  		return super.visit(wildcardQuery, termField);
  	}
  }
  